1. Field of the Invention
The present invention relates to an exposure control unit that controls the exposure of an imaging apparatus, such as a camera.
2. Description of the Related Art
It is known that an exposure of a camera is controlled on the basis of brightness measured by a photometer. It is preferable to control the exposure so that a desired subject is clearly photographed. For the purpose of such an exposure control, the photometer needs to detect a quantity of light from the desired subject.
On taking a photograph, generally not only the desired subject but often other items or scenes are also included in an area to be photographed. Accordingly, dividing the area to be photographed into photometric zones, detecting the quantities of light in each individual photometric zone, and using the quantity of light from one of the nine photometric zones to control the exposure is recommended for photographing with adequate brightness.
In addition, it is known that the desired subject is automatically estimated on the basis of the detected quantities of light in the divided areas, and that the exposure is controlled with respect to the estimated subject. For example, Japanese Unexamined Patent Publication No. 2004-109605 discloses various exposure controls with respect to a subject under a rear-lighting condition.
However, a photometer has been used in a prior art for a divided area that has a scene with a large quantity of light and a subject with a small quantity of light. In this situation it is difficult to accurately detect the quantity of light of the desired subject. As a result, it is difficult to control the exposure accurately.